New Options Upcoming for Treating Platinum-Resistant Ovarian Cancer

Erika P. Hamilton, MD, director of the Breast Cancer and Gynecologic Research Program and principal investigator at Sarah Cannon Research Institute, discusses unmet needs in treatment options for patients with platinum-resistant ovarian cancer due to the difficulty of early discovery, and what treatment options may become viable in the future.

The lack of effective screening tests for ovarian cancer leads to late-stage diagnoses with fewer treatment options, according to Hamilton. Ovarian cancer screening is often not recommended due to the nonspecific symptoms of the disease, plus a high rate of false positives from a transvaginal ultrasound screening or serum cancer antigen 125 testing.

Patients that experience a relapse of ovarian cancer after standard-of-care treatment within 6 months are classified as platinum-resistant, so other therapies are required at this point. Hamilton says combinations of chemotherapy with antiangiogenesis drugs, including VEGF inhibitors such as bevacizumab (Avastin), are being investigated in this setting. PARP inhibitors and immunotherapy are currently available as well. She also anticipates success with antibody-drug conjugates, which target antigens that are highly expressed on the membrane surface of tumor cells, making them more effective at avoiding harm to non-cancerous tissues.

Transcription:

0:08 | Ovarian cancer is a difficult disease for a number of reasons. First, there's no good screening test for ovarian cancer, so oftentimes, when people get diagnosed with ovarian cancer, they present later lines: stage III, stage IV. Most patients respond quite well initially to carboplatin-type agents; Taxol [paclitaxel] and carboplatin combined is most often what we give up front. But unfortunately, a lot of patients—well over 50% of our patients—end up relapsing. Once patients relapse within 6 months of their most recent platinum-containing compound is when we deem them platinum-resistant, and this is probably the greatest unmet medical need—more drugs in this space.

There are a lot of drugs out there that we're looking at, certainly combinations like this with chemotherapy and antiangiogenesis drugs. We now have PARP inhibitors for ovarian cancer. We've looked at immunotherapy, although the results on that have been a bit mixed, and then another new class of drugs coming to ovarian cancer that we're probably going to see some successes in are the antibody-drug conjugates, where we have chemotherapy that's bound to an antibody to help target the cancer cell and leave some of the rest of the body alone.